Fluid supported hoist



March 11, 1969 R. VAN GAASBECK 3,432,040

FLUID SUPPORTED HOIST Filed Nov. 15, 1967 50 COMPRESSOR INVENTOR RICHARD L. MIVGAASBECK ATTORNEX United States Patent Claims ABSTRACT OF THE DISCLOSURE A hoist apparatus comprising an overhead support and a mounting assembly, carrying a lift hoist, Which is fluid supported on the overhead support.

Background of the invention The present invention relates to hoist apparatus and more particularly to hoist apparatus of the type comprising a lift hoist suspended from an overhead support.

In conventional hoist apparatus of this type, the lift hoist is normally mounted on the overhead support by a hoist trolley having wheels movably supported on a generally horizontally extending wall of the support. This employment of a wheeled trolley for mounting the lift hoist is, however, subject to certain deficiencies and disadvantages. For example, during the movement of the hoist (and frequently a hoist carried load) longitudinally along the overhead support, the contact of the trolley wheels with the overhead support provides an undesirable source of friction which increases the pulling force necessary to move the hoist. In addition, the employment of a wheeled trolley for mounting the lift hoist necessitates numerous moving parts which must be periodically lubricated for their satisfactory operation.

Summary of the invention The principal object of the present invention is to provide a new and improved hoist apparatus of the aforedescribed type which is particularly constructed and arranged such that the lift hoist is supported on the overhead support without the necessity for trolley wheels or similar moving parts.

This object, and those other objects and advantages of the invention which will be apparent from the following description taken in connection with the accompanying drawings, are attained by the provision of a hoist apparatus wherein the lift hoist is fluid supported on the overhead support. More particularly, this hoist apparatus comprises an overhead support having a generally horiz0ntally extending wall, and a mounting assembly, having a wall above the support wall and opposing the latter, which is vertically movable relative to the overhead support. The lift hoist is carried by the mounting assembly such that it depends therefrom; and a means is provided for supplying pressurized fluid, preferably pressurized air, intermediate the support wall and the mounting assembly wall whereby the fluid provides a fluid cushion between these walls which supports the mounting assembly on the overhead support.

Brief description of the drawings FIG. 1 is an elevational view of a hoist apparatus constructed in accordance with the present invention;

FIG. 2 is an enlarged fragmentary elevational view showing the lift hoist and overhead support of such hoist apparatus; and

FIG. 3 is an enlarged elevational sectional view taken on line 33 of FIG. 2 looking in the direction of the arrows.

Description of the preferred embodiment Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, FIG. 1 illustrates a hoist apparatus comprising an overhead support 10 which is rigidly mounted on a supporting framework 12 to extend generally horizontally above the level of the ground or floor 14. The overhead support 10, as illustrated, is an I-beam arranged to include a vertical trunk or body 10b, an upper flange or base 10a directly connected to the supporting framework 12, and a lower flange which includes walls 100, 102 extending generally horizontally from opposing sides of the body 10b.

The lift hoist 16 of the hoist apparatus is of conventional construction and includes a casing 16a containing a circumferentially grooved drum 18 having wound thereon a hoisting cable 20 which carries a lift hook 22. The drum 18 is rotatable to vary the effective length of the hoisting cable 20 by a motor, designated generally as 24, which is selectively operable by a control handle 26 depending from an operating cable 28.

The lift hoist 16 is mounted on the overhead support 10 by a mounting assembly, designated generally as 30, which is illustrated in detail in FIG. 3. The mounting assembly 30 comprises a pair of spaced supporting or side plates 32, 34 which include lower end flanges 32a, 34a and upper end flanges 32b, 34b, respectively. The lower end flanges 32a, 32b are rigidly connected to opposing sides of the lift hoist casing 16a by a connecting means, illustrated as a pair of bolts 36 and cooperating nuts 38, and serve to connect the mounting assembly 30 to the lift hoist 16. The upper end flanges 32b, 3411 are connected by bolts 40, 42 to open bottomed, cushion blocks 44, 46, respectively, which are spaced a distance greater than the width of the body 1012 of the overhead support 10.

The mounting assembly 30 is mounted on the overhead support 10, for limited vertical movement relative thereto, with the body 10b projecting between the cushion blocks 44, 46 and the lower flange 100 located in the cavity 47 which is peripherally defined by the side plates 32, 34, the cushion blocks 44, 46, and the upper end of the hoist casing 16a. This arrangement, as will be seen from FIG. 3, positions the upper walls 44a, 46a of the cushion blocks 44, 46, respectively, above and opposite the walls 100, 1tl2 of the lower flange 10c. This arrangement, moreover, causes the upper walls 44a, 46a to each cooperate with the side walls 44b, 46b of their respective cushion block 44, 46 and their opposing one of the walls 100, 102 to peripherally define a chamber 48. Thus, as will be seen, the upper wall 44a and side walls 44b of the cushion block 44 cooperate with the wall 102 of the flange 10c to define a chamber 48 on one side of the body 1% of the overhead support 10; and the upper wall 461: and the side walls 46b of the cushion block 46 cooperate with the wall 100 of the flange 100 to define a chamber 48 on the opposing side of such body 10b.

The mounting assembly 30, and its carried lift hoist 1.6, are supported on the overhead support 10 by pressurized air supplied to these chambers 43. More particularly, as illustrated in FIG. 1, a conventional air compressor 50 is connected by a pneumatic supplyhose 52, containing a conventional one-way check valve '54, to an air supply bore 56 formed transversely through the side plate 32. The air supply bore 56 is, in turn, connected to the chamber 48 on the right side (as viewed in FIG. 3) of the body 10b :by a bore 58, and also connected to the chamber 48 on the left side (as also viewed in FIG. 3) of the body 1% by a hose 60 and a bore 62 formed in the side plate 34.

In the operation of the illustrated hoist apparatus, the compressor 50 is continuously operated to supply pressurized air through the air supply hose 52 to the chamber 48. The pressurized air, thus introduced into the chambers 48, becomes enclosed therein, whereby it raises the mounting assembly 3% (and carried lift hoist 16) and supports such on the overhead support 10. (The portion of the pressurized air flowing from the chambers 48 into the section of the cavity 47 beneath the lower flange ltic, of course, is exhausted to atmosphere as is also the minor portion of the pressurized air which tflows through the spaces between the cushion blocks 44, 4 6 and the body 1%.) The check valve 54- prevents reverse flow of the pressurized air in the air supply hose and, thereby, ensures that the pressurized air is not abruptly exhausted from the chambers 48 in the event of failure of the compressor 56. Furthermore, as the mounting assembly 30 is supported on the overhead support 10 by the pressurized air in the chambers 48, there is no frictional engagement between the mounting assembly 30 and the overhead support it). Thus, only minimal pulling force is required to move the lift hoist 16 and mounting assembly 39 longitudinally on the overhead support it).

From the aforegoing description it will be seen that I have provided new and improved means for accomplish ing all of the objects and advantages of my invention. It will be understood, however, that, although I have illustrated and hereinbefore specificially described only one embodiment of my invention, my invention is not limited merely to this single embodiment but rather con templates other embodiments and variations within the scope of the following claims.

Having thus described my invention, I claim:

1. A hoist apparatus comprising:

an overhead support having a generally horizontally extending wall;

a mounting assembly having a wall above said support wall and opposing the latter, said mounting assem bly being vertically movable relative to said overhead support;

a lift hoist carried by said mounting assembly and depending therefrom; and

means for supplying pressurized fluid intermediate said support wall and said mounting assembly wall whereby the fluid provides a fluid cushion between said walls which supports said mounting assembly on said overhead support.

2. A hoist apparatus according to claim 1 wherein said supporting wall longitudinally extends a distance sufficient to permit said mounting assembly to be moved longitudinally thereon.

3'. A hoist apparatus according to claim 1 wherein said fluid supply means comprises an air compressor and conduit means for supplying pressurized air from said compressor intermediate said walls.

4. A hoist apparatus according to claim 3 wherein valve means are provided for controlling the flow of air through said conduit means.

5. A hoist apparatus comprising:

an overhead support having a generally horizontally extending wall;

a mounting assembly having a wall above said support wall and cooperating with said support to peripherally define a chamber bounded at its upper and lower ends by said mounting assembly wall and said support wall, respectively, said mounting assembly being limitedly vertically movable relative to said overhead support;

a lift hoist carried by said mounting assembly and depending therefrom; and

means for supplying pressurized fluid to said chamber whereby the fluid becomes enclosed in said chamber and provides a fluid cushion which supports said mounting assembly on said overhead support.

6. A hoist apparatus according to claim 5 wherein said overhead support comprises a plurality of generally horizontally extending walls, said mounting assembly includes a wall above each of said support walls and cooperates with said overhead sup-port to peripherally define a chamber above each of said support walls, and said fluid supply means comprises means for supplying pressurized fiuid to each of said chambers.

7. A hoist apparatus according to claim 6 wherein said fluid supply means comprises an air compressor and conduit means for supplying pressurized air from said compressor to each of said chambers.

3. A hoist apparatus according to claim 7 wherein said support walis each extend longitudinally a distance suflicient to permit movement of said mounting assembly longitudinally on said overhead support.

9. A hoist apparatus comprising:

an overhead support including a trunk and a pair of generally horizontal walls projecting in opposite directions from said trunk;

a mounting assembly having a wall above each of said support walls and cooperating with said overhead support to peripherally define a chamber intermediate each of said support walls and its respective adjacent mounting assembly wall, said mounting assembly being limitedly vertically movable relative to said overhead support;

a lift hoist carried by said mounting assembly and depending therefrom; and

means for supplying pressurized air to each of said chambers whereby the air becomes enclosed in said chambers and provides therein fluid cushions which support said mounting assembly on said overhead support; and

said support walls longitudinally extending a distance sufiicient to permit movement of said mounting assembly longitudinally on said overhead support.

10. A hoist apparatus according to claim 9 wherein valve means are provided for controlling the flow of pressurized air to said chambers.

References Cited UNITED STATES PATENTS 1/1965 Mackie 212l34 5/1968 Thireau 74207 U.S. Cl. X.R. 254168 

